Chemical mechanical polishing fastening device

ABSTRACT

A chemical mechanical polishing fastening device includes an annular base and a fastening ring. The annular base has a first combining plane, a first inner annular plane, a first jointing plane, and a second inner annular plane. The diameter of the first inner annular plane is greater than that of the second inner annular plane. Two sides of the first inner annular base are connected to the first combining plane and the first jointing plane. Two sides of the first jointing plane are connected to the first inner annular plane and the second inner annular plane. The fastening ring has a second combining plane and an inner annular flange protruded from the second combining plane. The inner annular flange has an outer annular wall to be combined with the first inner annular plane and a top plane to be combined with the first jointing plane.

CROSS-REFERENCES TO RELATED APPLICATIONS

This non-provisional application claims priority under 35 U.S.C. §119(a)on Patent Application No. 103221659 filed in Taiwan, R.O.C. on 2014 Dec.5, the entire contents of which are hereby incorporated by reference.

BACKGROUND

1. Technical Field

The instant disclosure relates to a chemical mechanical fastening ring,in particular, to a chemical mechanical polishing fastening deviceapplied for polishing semiconductor wafers.

2. Related Art

Chemical mechanical polishing is an essential procedure duringmanufacturing the semiconductors. If the wafers cannot be polishedproperly or if scratches left on the wafers, process error would occurduring the subsequent lithography procedure like exposure, develop, andetching. In some situation, unrecoverable defects may be formed on thewafers.

In a traditional chemical mechanical polishing device, a fastening ringwith a specific thickness faces and is adhered to a base whose shape iscorresponding to the ring. In general, the fastening ring is made ofpolymers and provided for securing a wafer to be polished. During thechemical mechanical polishing procedure, the fastening ring has tosustain the wearing from the high-rotational-speed polishing pad, andfastening ring also has to suffer the erosion from the chemicalmechanical polishing liquid. Therefore, after the fastening ring is usedfor a certain times, the fastening ring has to be replaced by another.

In practice, with a certain possibility, the fastening ring may befailure ahead of the predicted life time (early life failure). Thereason is described as follows. During polishing procedure, the chemicalmechanical polishing liquid may enter into the interface between thefastening ring and the base, the adhesive in the interface would becomesmall particles by reacting with the polishing liquid and then theparticles spread in the polishing liquid. Therefore, during thepolishing procedure, the small particles in the polishing liquid wouldrub against the surface of the wafer to produce scratches on the wafer.As a result, the fastening ring would be failure ahead of the schedule.Accordingly, the replacement times of the fastening ring and thedowntime of the production line are increased. Consequently, thematerial cost and the manufacturing cost of the wafer subcontractorswould be increased at the same time.

Therefore, the chemical mechanical polishing liquid would enter theinterface between the fastening ring and the base so as to make thefastening ring be early life failure and to cause the increasing of thematerial cost and the manufacturing cost of the wafer subcontractors.

SUMMARY

In view of these, an exemplary embodiment of the instant disclosureprovides a chemical mechanical polishing fastening device comprising anannular base and a fastening ring. The annular base comprises a firstcombining plane, a first inner annular plane, a first jointing plane,and a second inner annular plane. The first combining plane is parallelto the radial direction of the annular base. The diameter of the firstinner annular plane is greater than the diameter of the second innerannular plane. Two sides of the first inner annular base are connectedto the first combining plane and the first jointing plane, respectively.Two sides of the first jointing plane are connected to the first innerannular plane and the second inner annular plane, respectively. Thefastening ring comprises a second combining plane and an inner annularflange. The second combining plane is parallel to the radial directionof the fastening ring. The second combining plane is combined with thefirst combining plane of the annular base. The inner annular flange isprotruded from the second combining plane. The inner annular flange hasan outer annular wall and a top plane. The outer annular wall iscombined with the first inner annular plane of the annular base, and thetop plane is combined with the first jointing plane.

In one implementation aspect according to the instant disclosure, thedistance between the top plane of the inner annular flange and thesecond combining plane of the fastening ring is defined in the rangefrom 5 mm to 15 mm.

In one implementation aspect according to the instant disclosure, thethickness of the inner annular flange along the radial direction of thefastening ring is defined in the range from 1 mm to 5 mm.

In one implementation aspect according to the instant disclosure, theinner annular flange has an inner annular wall. The inner annular wallof the inner annular flange and the second inner annular plane arealigned at the same level.

In one implementation aspect according to the instant disclosure, anominal fillet radius of 1.5 mm is defined at the connection between thefirst jointing plane and the first inner annular plane.

In one implementation aspect according to the instant disclosure, theannular base further comprises a first outer annular plane, a secondjointing plane, and a second outer annular plane. The diameter of thefirst outer annular plane is less than that of the second outer annularplane. Two sides of the first outer annular plane are connected to thefirst combining plane and the second jointing plane, respectively. Twosides of the second jointing plane are connected to the first outerannular plane and the second outer annular plane, respectively.

In one implementation aspect according to the instant disclosure, thefastening ring comprises an outer annular flange protruded from thesecond combining plane. The outer annular flange has an inner annularwall and a second top plane. The inner annular wall is combined with thefirst inner annular plane of the annular base, and the second top planeis combined with the first jointing plane.

In one implementation aspect according to the instant disclosure, thedistance between the second top plane of the outer annular flange andthe second combining plane of the fastening ring is defined in the rangefrom 4 mm to 10 mm.

In one implementation aspect according to the instant disclosure, thethickness of the outer annular flange along the radial direction of thefastening ring is defined in the range from 1 mm to 4 mm.

In one implementation aspect according to the instant disclosure, theouter annular flange has an outer annular wall. The outer annular wallof the outer annular flange and the second outer annular plane of theannular base are aligned at the same level.

Detailed description of the characteristics and the advantages of thedisclosure is shown in the following embodiments, the technical contentand the implementation of the disclosure should be readily apparent toany person skilled in the art from the detailed description, and thepurposes and the advantages of the disclosure should be readilyunderstood by any person skilled in the art with reference to content,claims and drawings in the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The instant disclosure will become more fully understood from thedetailed description given herein below for illustration only, and thusnot limitative of the instant disclosure, wherein:

FIG. 1 is a perspective view of a traditional chemical mechanicalpolishing fastening device;

FIG. 2 is a sectional view along line 1-1 of FIG. 1;

FIG. 3 is an exploded view of a chemical mechanical polishing fasteningdevice of an exemplary embodiment of the instant disclosure;

FIG. 4 is a perspective view of the chemical mechanical polishingfastening device;

FIG. 5 is a sectional view along line 2-2- of FIG. 4; and

FIG. 6 is an operational view of the chemical mechanical polishingfastening device.

DETAILED DESCRIPTION

Please refer to FIG. 1 and FIG. 2, illustrating a perspective view and asectional view of a typical chemical mechanical polishing fasteningdevice 9 including a base 91, a fastening ring 92, and a jointing plane93 between the base 91 and the fastening ring 92. Typically, the base 91and the fastening ring 92 are combined with each other by sticks.Nevertheless, the chemical mechanical polishing liquid would enter intothe space between the base 91 and the fastening ring 92 from thejointing plane 93, such that the fastening ring 92 made of polymers(e.g., Polyphenylene sulfide, PPS), may be failed ahead of the predictedtime. Therefore, one of the important concepts of the embodiment is toprovide a technical solution to prevent the chemical mechanicalpolishing liquid from entering into the space between the base 91 andthe fastening ring 92 during the chemical mechanical polishingprocedure.

Please refer to FIG. 3, FIG. 4, and FIG. 5, which provide an explodedview, a perspective view, and a sectional view of a chemical mechanicalpolishing fastening device 1 according to an exemplary embodiment of theinstant disclosure. The chemical mechanical polishing fastening device 1comprises an annular base 11 and a fastening ring 12. When a wafer isprocessing the chemical mechanical polishing procedure, the fasteningring 12 faces down to frame the wafer within the fastening ring 12.

The annular base 11 comprises a first combining plane 111, a first innerannular plane 112, a first jointing plane 113, a second inner annularplane 114, a plurality of engaging blocks 118, and a plurality of lockholes 119. The first combining plane 111 is parallel to the radialdirection of the annular base 11. The diameter of the first innerannular plane 112 is greater than the diameter of the second innerannular plane 114. As shown in FIG. 3, two sides of the first innerannular plane 112 are connected to the first combining plane 111 and thefirst jointing plane 113, respectively. In other words, two sides of thefirst inner annular plane 112 are connected, in a one-to-onerelationship, to the first combining plane 111 and the first jointingplane 113. The first jointing plane 113 is substantially parallel to thefirst combining plane 111, and two sides of the first jointing plane 113are connected to the first inner annular plane 112 and the second innerannular plane 114, respectively. In other words, two sides of the firstjointing plane 113 are connected, in a one-to-one relationship, to thefirst annular plane 112 and the second inner annular plane 114. Besides,a nominal fillet radius of 1.5 mm to 2.0 mm is defined at the connectionbetween the first jointing plane 113 and the first inner annular plane112. The engaging blocks 118 are fastened on the first combining plane111 of the annular base 11 via screws passing through the lock holes119.

The fastening ring 12 comprises a second combining plane 121, aplurality of engaging holes 128, and an inner annular flange 129. Thesecond combining plane 121 is parallel to the radial direction of thefastening ring 12. The second combining plane 121 is combined with thefirst combining plane 111 via the engagements between the engagingblocks 118 and the engaging holes 128. Alternatively, the combinationbetween the fastening ring 12 and the annular base 11 may be furtherenhanced by applying adhesive to the interface between the firstcombining plane 111 and the second combining plane 121.

The inner annular flange 129 is protruded from the second combiningplane 121. The inner annular flange 129 has an outer annular wall 129 aand a top plane 129 b. As shown in FIG. 5, the outer annular wall 129 ais combined with the first inner annular plane 112 of the annular base11, and the top plane 129 b is combined with the first jointing plane113.

Please refer to FIG. 6, which provides an operational view of thechemical mechanical polishing fastening device 1 according to theexemplary embodiment of the instant disclosure. The chemical mechanicalpolishing fastening device 1 is fixed to a chemical mechanical polishingapparatus 6 so as to be rotatable relative to a polishing pad (notshown) therebeneath, and a wafer 7 is framed within the fastening ring12. During the polishing procedure, the chemical mechanical polishingliquid may possibly pass through the space between the wafer 7 and thefastening ring 12 to be accumulated at the back of the wafer 7. In theexemplary embodiment of the instant disclosure, since the fastening ring12 further comprises the inner annular flange 129, the second combiningplane 121 is combined with the first combining plane 111 of the annularbase 11, the outer annular wall 129 a is combined with the first innerannular plane 112 of the annular base 11, and the top plane 129 b iscombined with the first jointing plane 113 of the annular base 11.Accordingly, when the wafer 7 is polishing, the chemical mechanicalpolishing liquid 8 accumulated at the back of the wafer 7 may solelyenter the space between the annular base 11 and the fastening ring 12from the connection between the first jointing plane 113 and the topplane 129 b of the inner annular flange 129. However, since theconnection between the first jointing plane 113 and the top plane 129 bof the inner annular flange 129 is so distant from the back of the wafer7, the chemical mechanical polishing liquid 8 will generally not enterinto the space between the fastening ring 12 and the annular base 11.

As compared with the traditional chemical mechanical polishing device,the fastening ring 12 according to the exemplary embodiment of theinstant disclosure would not be failure ahead of the predicted lifetime. Therefore, the problems in increasing of the material cost and themanufacturing cost of the wafer subcontractors can be solved.

Experiments verify that when the distance between the top plane 129 b ofthe inner annular flange 129 and the second combining plane 121 of thefastening ring 12 is equal to or greater than 5 mm (for example 15 mm),the early failure of the fastening ring 12 can be apparently reduced.When the distance is equal to or greater than 10 mm, the fastening ring12 is not failure ahead of the scheduled time anymore.

In addition, when the thickness of the inner annular flange 129 alongthe radial direction of the fastening ring 12 is defined to be equal toor greater than 1 mm, the structural strength of the inner annularflange 129 can be enhanced, and the inner annular flange 129 would notbe broken easily. Therefore, the connection between the first jointingplane 113 of the annular base 11 and the top plane 129 b of the innerannular flange 129 would have a certain structural strength to bear theshearing stress generated at the connection between the first jointingplane 113 and the top plane 129 b during the chemical mechanicalpolishing procedure. Experiments further verify that when the thicknessof the inner annular flange 129 along the radial direction of thefastening ring 12 is defined in the range from 1 mm to 5 mm, thestructural strength of the inner annular flange 129 can be enhanced.

In one implementation of the exemplary embodiment, as shown in FIG. 5,the inner annular flange 129 has an inner annular wall 129 c. The innerannular wall 129 c of the inner annular flange 129 and the second innerannular plane 114 of the annular base 11 are aligned at the same level.If the inner annular wall 129 c and the second inner annular plane 114does not align at the same level, for example, if the area of the topplane 129 b is greater than that of the first jointing plane 113, a fewchemical mechanical polishing liquids 8 would be accumulated at the topplane 129 b of the inner annular flange 129 with an extremely smallpossibility. Then, with the centrifugal force generated upon therotation, the chemical mechanical polishing liquid 8 would enter insidethe fastening ring 12 through the space between the top plane 129 b andthe first jointing plane 113. Conversely, in the case that the innerannular wall 129 c and the second inner annular plane 114 are aligned atthe same level, even when a small amount of chemical mechanicalpolishing liquid 8 has already been spread to the space between the topplane 129 b and the first jointing plane 113, the chemical mechanicalpolishing liquid 8 does not enter inside the fastening ring 12.

While the instant disclosure has been described by way of example and interms of the preferred embodiments, it is to be understood that theinvention needs not be limited to the disclosed embodiments. For anyoneskilled in the art, various modifications and improvements within thespirit of the instant disclosure are covered under the scope of theinstant disclosure. The covered scope of the instant disclosure is basedon the appended claims.

What is claimed is:
 1. A chemical mechanical polishing fastening device,comprising: an annular base, comprising a first combining plane, a firstinner annular plane, a first jointing plane, and a second inner annularplane, wherein the first combining plane is parallel to the radialdirection of the annular base, the diameter of the first inner annularplane is greater than the diameter of the second inner annular plane,two sides of the first inner annular plane are connected to the firstcombining plane and the first jointing plane, respectively, two sides ofthe first jointing plane are connected to the first inner annular planeand the second inner annular plane, respectively; and a fastening ring,comprising a second combining plane and an inner annular flange, whereinthe second combining plane is parallel to the radial direction of thefastening ring, the second combining plane is combined with the firstcombining plane of the annular base, the inner annular flange isprotruded from the second combining plane, the inner annular flange hasan outer annular wall and a top plane, the outer annular wall iscombined with the first inner annular plane of the annular base, and thetop plane is combined with the first jointing plane.
 2. The chemicalmechanical polishing fastening device according to claim 1, wherein thedistance between the top plane of the inner annular flange and thesecond combining plane of the fastening ring is defined in the rangefrom 5 mm to 15 mm.
 3. The chemical mechanical polishing fasteningdevice according to claim 2, wherein the thickness of the inner annularflange along the radial direction of the fastening ring is defined inthe range from 1 mm to 5 mm.
 4. The chemical mechanical polishingfastening device according to claim 3, wherein the inner annular flangehas an inner annular wall, the inner annular wall of the inner annularflange and the second inner annular plane are aligned at the same level.5. The chemical mechanical polishing fastening device according to claim4, wherein a nominal fillet radius of 1.5 mm to 2.0 mm is defined at theconnection between the first jointing plane and the first inner annularplane.